It’s not that I disagree, I just don’t know enough about the Star Trek side of the equation to say for sure, but I can definitely see some overlap.

We’ve got several backstory ideas for highland Trolls in this series. Hopefully some of those will be helpful in fleshing out the character. Of course your friend can also play a lowland Troll. Much of this info would still apply, but lowland Trolls would tend to be less extreme in a lot of ways, making them easier to work into a campaign.